This study focuses on the analysis of delay factors which affect the delay in construction completion in Benin in order to teach construction project managers a specific managerial method that would be very useful for the success of new development projects. In this respect, some Beninese construction experts have been interviewed about some construction projects: departmental hospital, administration office, school, community health care center and community market done in the past and located in Cotonou, Porto-Novo, Abomey and Parakou. After statistical data of frequency, severity and importance was analyzed, an index of thirty-five delay factors were identified and used in structured questionnaires that were sent to the construction managers (contractor, owner, consultant and architect). The top ten important delay factors by their rank were further identified as: Financial capability by contractor, financial difficulties by owner, poor subcontractor performance, materials procurement of contractor, changes in drawings of architect, inadequate planning and scheduling of contractor, slow inspection of completed works by the consultant, equipment availability of contractor, preparation, approval of drawings of consultant and acceptance of inadequate design drawings by consultant. A comparison of the top five delay factors of Benin construction projects requiring a time extension with selected construction projects in Asia and other African countries shows that financial difficulty is most common, especially in African countries. Other causes of delay are very similar for developing countries and related to lack of technology, management, skills and competencies of project participants. Therefore it has been concluded that construction time overrun depends on economic, political stability and management implementation in each country. The study can be extended to compare other African countries development construction project delay factors to Asian countries.

An extensive network of pipeline systems is used to transport and distribute national energy resources that heavily influence a nation’s economy. Therefore, the structural integrity of these pipeline systems must be monitored and maintained. However, structural damage detection remains a challenge in pipeline engineering. To this end, this study developed a modified electromechanical impedance (EMI) technique for crack detection that involves fusing information from multiple sensors. We derived a new damage-sensitive feature factor based on a pipeline EMI model that considers the influence of the bonding layer between the EMI sensors and pipeline. We experimentally validated the effectiveness of the proposed method. Finally, we used a damage index—root mean square deviation—to examine the degree and position of crack damage in a pipeline.

A method for monitoring the upheaval buckling of subsea buried pipelines by distributed optical fiber sensors is introduced. The proposed method originates from the fact that the bucked pipe has the deterministic patterns of the bending-induced and axial force–induced strains, which can be used to identify the pre- and post-buckling states of the pipe. The challenge for utilizing these features is that the distributed fiber optic sensor can only measure the compound strain created by both bending and axial compression. A monitoring scheme by placing three sensors with $2\pi /3$ space around the circumference of the pipeline was proposed in this article. An approach was presented to extract the bending-induced and axial force–induced strains from the longitudinal strains measured by the distributed fiber optic sensors. The experimental programs were then designed to investigate the feasibility of the proposed method. It is demonstrated that the proposed method is possible to detect the occurrence of buckling in the pipe. However, further research is necessary in order to examine the efficiency of the proposed approach under the complex loading patterns at subsea levels.